Tube expanding roller mill



R. BUNGEROTH TUBE EXPANDING ROLLER MILL May l,l 1934.

Filed June 4, 1930 l@ li Patented May -l, 1934 UNITEDSTATES PATENT OFFICE Application June 4, 1930, Serial No. 459,175 In Germany November 26, 1929 3 Claims. (Cl. 80-11) This invention is for improvements in or relating to tube expanding roller mills and more particularly to apparatus arranged to move tubes into engagement with the rolls of such mills in 5 which the mandrel rod is stressed tensionally during the rolling operation. A

With roller mills of this character a tube to be rolled is placed in position and the mandrel rod is then passed through the tube and connected with a lock therefor. When the mandrel rod has been passed through the tube in the manner described the tube is located at a certain distance from the rolls and it is necessary to move the tube towards the rolls until they grip the end of the tube in conjunction with the mandrel, vwhereupon the rolling operation is commenced.

According to the invention there is provided a roller mill of the type set forth wherein a tube which has been placed in position around the mandrel rod is arranged' to be moved into engagement with the rolls of the mill by a driving head which is adapted to support the said rod between the ends thereof.

Inorderthat the invention may be fully understood reference is directed to the accompanying drawing, in which:-

Figure 1 is a vertical longitudinal section of a portion of a roller mill constructed in accordance with this invention.

Figure 2 is a view similar to Figure l, but with some of the parts in different positions and Figure 3. is a plan view of Figure 1.

Referring to the drawing, Figure l shows a tube a placed in position relatively to rolls c, c1 of the mill after a mandrel rod b has been passed through the tube andconnected to a lock c so that a mandrel d provided upon the free end of the rod b is positioned between the rolls c, c1.

Rollers f are arranged to support the mandrel rod when the tube a is in the position shown in Figure 1.

A guide g is provided arranged to guide the tube centrally with relation to the mandrel d when entering into engagement with the rolls and during the rolling operation. The introduction of the tube into engagement with the rolls is effected by means of a driving head h which may be actuated. in any desired manner as, for example, by hydraulic apparatus, The driving head h. is slidably mounted upon guides provided in the mill frame and is arranged to surround the mandrel rod b and act as a support therefor. In the operation of this apparatus the tube a is moved from the initial position shown in Figure 1 by the driving head h into engagement withthe rolls c, c1 as shown in Figure 2 and it will be observed that as the driving head approaches the said rolls the sag of the mandrel rod is correspondingly decreased until the driving head supports the said rod midway between the ends thereof, at which point the head remains while the tube is drawn through the rolls '4 by the rolling operation. As shown in the drawing, when the driving head has been advanced to the end of its slide it will be at the mid-portion of the mandrel. I

The supporting surfaces in the driving head h upon which the mandrel rod rests may be fixed surfaces as shown in the drawing or movable, for example in the form of rollers.

I claim:

1. A tube expanding roller mill comprising a plurality of rolls forming an expanding pass, a mandrel cooperating therewith to expand a tube without material reduction in wall thickness, a long, slender mandrel rod secured at` one end supporting the mandrel at the other end and adapted to receive an elongated, thin-walled tube between its ends, tube pushing means movable along said rod from its secured end to a position sufficient to push a tube between the bight of the rolls, said pushing means including means l for engaging the underside of said mandrel rod to prevent the same from sagging, whereby said rod is supported during the movement of the pushing means for feeding the tube to the rolls and at a medial stationary point while the tube is passed thereafter through such rolls.

2. A tube expanding roller mill comprising a i plurality of rolls forming an expanding pass, a mandrel cooperating therewith to expand a tube without material reduction in wall thickness, a long, slender mandrel rod secured at one end supporting the mandrel at the other end and adapted to receive an elongated, thin-walled tube between its ends, tube pushingv means movable along said rod from its secured end to a position sufficient to push a tube between the bight of the rolls, said pushing means including means for engaging the underside of said mandrel rod to prevent the same from sagging, whereby said rod is supported during the movement of the pushing means for feeding the tube to the rolls and at a medial stationary point while the tube is passed thereafter through such'rolls, and a guide arranged in advance of the rolls` and mandrel to receive the forward end of the tube to be rolled and guide the same toward the mandrel and rolls.

bight of the rolls, said pushing means including means for engaging the underside of said mandrel rod to prevent the same from sagging. whereby said rod is supported during the movement of the pushing means for feeding the tube to the rolls and at a medial stationary point while the tube is passed thereafter through such rolls, and hydraulically actuated means for operating said tube pushing means.

RUDOLF BUNGEROTH, 

